1. Field
The present invention relates generally to infusion devices used for the administration of various fluids and medications to patients. More specifically, embodiments of the present invention are directed to an infusion check valve assembly for an intravenous catheter.
2. Related Art
The use of intravenous devices for the administration of parenteral and other fluids to patients is a common practice. A variety of devices for such purposes have been proposed in the past, such as a simple length of tubing having a fitting on one end for making connection with a source of fluid (e.g., a bottle or flexible bag), while the other end is provided with a needle or catheter that may be inserted into the vein of a patient. A persistent problem with prior infusion devices is referred to as fluid reflux, or the tendency for fluids, such as blood or medication, to be drawn into the infusion apparatus. Fluid reflux can occur in prior art devices, for example, when a gravity supply fluid source is empty, when medication is infused through an adjacent component, or when a cannula is removed from a septum or port.
Prior art pressure-activated infusion devices that reduce fluid reflux using a flexible valve are problematic due to design and manufacture-related issues. Flexible valves may often times mechanically invert within the internal passage of the valve housing due to elevated back pressure. Upon such an inversion, the flexible valves may be forced into a permanently open position, thus permitting blood or other unwanted fluids and medication to reflux back through the valve. Prior art check valves, such as certain types of disc valves, used to reduce or restrict fluid reflux typically require high cracking pressures for incoming fluids to open and pass through the valves. In certain applications, high cracking pressures may be acceptable. However, in other applications, lower cracking pressures may be necessary. To reduce the cracking pressures in prior art check valves, the valves are often designed with large diameters, such that the valves present enough surface area to reduce the cracking pressures to acceptable levels. Although such prior art check valves may assist in reducing fluid reflux, because of the increased size of the valves, they may be inefficient, and often times impractical, for the intravenous administering of fluid and medication.
There is accordingly a need in the art for improved intravascular devices equipped with a check valve component that eliminates the possibility of fluid reflux, while providing for the efficient administration of medical fluids.